Conversion of hydrocarbon liquids



1,614 93o Jan 18 1927 A. J. PARIS, JR

CONVERSION 0F vHYDROCARBON ILIQUIDS Filed May 14. 1924 *Q ggf,

ATTORNEYS Patented l,

UNITED STATES AUGUSTE JEAN PARIS, JR., OF BRADFORD, PENNSYLVANIA.

CONVERSION OF HYDROCARBON LIQUIDS.

Application lcd May 14 This invention relates to the conversion of Ahydrocarbon liquids of higher boiling points, particularly from petroleum sources, into hydrocarbon liquids of lower boiling points and includes improved methods and apparatus for accomplishing` this conversion.

Thev conversion of hydrocarbon liquids intoA liquids of lower boiling points is a chemical change and may be eected by the application of heat or the application of heat and pressure while the hydrocarbons are in thel form of liquids or'vapors. The effect of any given conditions of temperature and pressure varies with different hydrocarbons,

and likewise, different conditions of temperature and pressure have varying effect upon the same hydrocarbon. This invention takes advantage -of these facts to accomplish 'a higher yield and a more uniform eo yield in the conversion of hydrocarbon liquids of higher boiling points into hydrocarbon liquids of lower boiling points than have hitherto been obtainable.

The character of the cracking, polymerization, decomposition, or other conversion effected when a group of hydrocarbons are` subjected to `the same conditions of temperature and pressure is'dierent Awith each of the components of that group. Distillates or fractions having a wide range of boiling points are. composed of component hydrocarbons having similarly widely varying pyrolytic characteristics. Conditions of temperature and pressure which would be best adapt-ed to effect the maximum conversion of the hydrocarbons constitutingthe higher boiling end of such a fraction to the desired product would not be best adapted to the treatment f the lower boiling end for the production of the same product and vice versa. The subjection in entirety of such distillates or fractions of wide boiling range to the 'same conversion conditions operates to treat only a small part of the distillate or fraction at optimum conversion conditions. The result of such treatment is that alarge portion of the hydrocarbon fraction is not converted to fractions of the desired characteristics, that large amounts' of p undesired .50 conversion products are produced, and that the recovery of the desired product is relatively low.

, 1924. Serial No. 713,230.

Hitherto it has been customary to submit hydrocarbon oils containing components having a wide range of boiling points to substantially uniform heating and conversion conditions resulting in a relatively low recovery.. For example, if a-characteristic water white kerosene having a boiling range of about 300 F. is subjected as a whole to conversion, only about 25% ofgasoline can ,be obtained under optimum conditions in a single operation. The same result is obtained4 when treating gas oil, fuel oil or any other of the-heavy distillates which have a similar wide range of boiling points. It is possible to -increase such yields by repetition of the conversion operation upon the separated residue, but such repetition does not improve the eliiciency of the conversion pper'ation itself and necessarily entails largel oss.

In the practice of this invention, hydrocarbon fractions having a narrow range of boilingpoints are subjected to optimum conversion conditions for the maximum production of the desired product. In this manner, improved results are obtained; for example, a larger yield of the desired product and a product of improved qualit-y becomes possible. This-invention is particularly adapted to conversion of the lower boiling petroleum* distillates, Such as kerosene, fuel oil and other petroleum fractions which normally contain no constitute'nts as volatile as gasoline into an oil which is as volatile as gasoline. Crude oil or residues or distillates which may or may not contain gasoline may be treated for the production of gasoline. l

According to this invention, `the hydrocarbon oil to be cracked is preliminarily distilled and the distillate subjected to appropriate conditions of temperature -and pressure tov effect cracking, polymerization, decomposition or other conversion, the boil- \ing range of the oil subjected to conversion being limited to less than about 100 F. at any one time, or more advantageously about 25 F. The distillate from the preliminary still may be continuously subjected to conversion, the conversion conditions beng appropriately varied as the character of the distillate changes, or'the distillate may be collected in limited fractions which are then subjected to conversion conditions appropriate to each fraction. The distillate from the preliminary still may be rst liquefied or nay be passed to the conversion operation as a vapor. v

The exact nature of the conversion operation proper is not a part of` this invention, but this invention may be employed in conjunction with any suitable cracking operation or apparatus. The oil may be cracked raw material being treated.

In the accompanying drawings Iy have illustrated' and in the following specification described, a preferred form of my invention but it will be understood that this specific vdisclosure is for the purpose of illustratino my invention and isv not t'o be construed as a limitation thereof. In the drawings, Fig. l is a somewhat diagrammatic and sectional view of an apparatus embodying the inventionv and particularly adapted to the practice of the invention and Fig. 2. is a fragmentary diagrammatic andsectional view of a modified form of th apparatus. l

Referring to the drawings, 10 represents a still. boiler or heater for the oil to be treated. The still 10 may be provided with a relief valve lland pressure gauge 12and may be heated by any suitable means as by burnerl providedvwith gas or liquid fuel through pipe 14. Pipe 16 may be connected to any desirable source of material to be treated, and connection 17 controlled by valve 18 is provided to conduct material to be treated to lthe still 10. Va o4 line 25 is provided to conduct the vap r from the still. Thereceiver26 provided with gauge 27 and draw off cock 28 is connected to the condenser or cooler 30 through valve 29 and may be placed in communication with line 25 through conduit 31 controlled by valve 32.l Receivers or collectors 35 and 36 are connected through valves 37, 38 and 40 to the condenser or cooler 4l which may be placed in communication with y line 25 through valve 43. Conduit 44 may be placed in communication with line 25 through valve 45.

Numeral 50 designates a pump, which in different embodiments of the invention may be required to operate under a pressure, a vacuum, or under a vacuum and a pressure on opposite sides of the'pump, end may be required to handle liquids in some instances and vapors in others. It will be understoodthat a single pump need not fulfill all of these requirements but that in each instance a pump satisfactory for the particular operation will he employed. All of these conditions may be encountered in treating different raw materials for the production of different end products in accordance with the invention.

Pump 50 transfers the hydrocarbons to the converting apparatus. Connection 52 to the inlet valve 51 of the pump' 50 may be placed in communication with either of receivers 35 and 36 through valves- 46 and 47 respectively, .with the connection to the source of material to be treated 16 lthrough valve 48 and pipe 19 or'.with vthe still 10 through connectionl 21 .controlled by valve 20. The exhaust valve 53 of the pump .50 communicateswith lthe interior of the converting tube 60 through connection 54, safety relief valve 55, lthermometer or pyrometer 56 and pressure gaugej57 being provided therein- Wheresuitable conditions prevail, the hydrocarbons may be introduced into the convertor through connection 115 provided with regulating valve 116 instead of through the pump. Raw oil from connection 16 may be supplied to tube 60 through pipe 58 controlled byV valve 59.

The converting or cracking retort illustrated com-prises the tube or pipe 60 preferably of steel or wrought iron with a cast iron jacket 61 cast thereon. This construction lengthens the life of the tube or pipe, assists in maintaining a uniform temperature, preserves the strength of the tube or pipe at high temperature and prevents the pipe or tube from twisting and getting out of shape, keeping the pipe or tube straight so that a bar or other suitable device may be pushed4 therethrough for the purpose of cleaning the pipe which in turn makes possible a more continuous operation. Removable cap 63 is provided over the end of pipe 60 to provide access for cleaning. The tube 60 may be heated by any suitable means, as by providing a stack 65 about the tube and passing hot gases from burner 66, there. through. Burner 66 may be provided with fuel through pipe 67 the combustion gases exhausted through flue 68. Advantageously, the flow of heating gases in countercurrent to the flow of the oil. Or the pipe 60, with or without the jacket 61, may be heated by immersion in a bath of molten metal such as molten lead which may in turn be heated by a fire. The tube 60 may be covered with heat insulation 69 external to the retort. A thermometer or pyrometer 70 may be provided in the tube 60.

The conversion apparatus as exemplified by the cracking retort 60, is not in itself a part of this invention but the invention may be carried out in apparatus of any s'uitable character adapted to subject the hydroar? bons to the necessary conversion conditions.

Tube or pipe 60 may be connected to any suitable separation or collection apparatus through connection 75, which may be a continuation of tube 60. This connection is here shown as conducting the cracked f 'or converted products into tower 80 provided With a safety relief valve 81, a thermometer or pyrometer 82, a liquid level gauge 83, a draw ofl cock 84 and a pressure gauge 85. Connection 86 controlled by valve 87 -is provided at the base of tower 80 whereby material may be returned through pipe 88 to still through connection-22 controlled by valve 23. Receiver 90,'provided with draw olf lill cock 91, liquid level gauge 92, safety relief .valve 93 and gas relief line 94 controlled by' valve 95, is connected to condenser 96 through valve 97 and may be placed in communication with the top of tower through connection 98 controlled bypvalve 99.

In Fig. 2 I have shown a modified form of apparatus embodying the invention. In this figure. 100 designates a conduit leading from a still or boiler such as still 10. This conduit communicates with -condenser 101 which in turn communicates through connection 103 controlled by valve 102 to receivers or stills 104 and 105 through valves 106 and 107 respectively. These receivers "or stills may be heated by any suitable means, as by' burners 108 and 109, and are provided with vapor lines 110 and 111 communicatingthrough condensers 112` and 113 'with receivers 114 andy 115 res ectively.

In the practice ofthe invention, I may prepare the oil to be converted by continuously passing the ldistillates from a still to and through theconverting zone, without permitting thedistillates havingend boiling points of a difference greater than 100 F. to mix withvany `other` distillates before entering the cracking apparatus. Ad-

' vantageously, the hydrocarbons entering the conversion chamber in either liquid or vapor form, should have end boiling points not more than 25 F. apart at any given instant and I aim to treat fractions approximating as closely as possible a single boiling point, that is, yof as narrow a boiling vrangev as In one method of carrying out this preliminar treatment, I employ a pump between t e still'and the cracking or converting apparatus for thc'purpose of transferring the distilled oil from the still to the converting apparatus as fast as it comes from the still, and to limit the capacity of the lines of communication betweenthe still and the pump to vless than about one fourth the total volume of hydrocarbons to be subjected to the process whereby to'limit the boiling range of the distillate submitted to conversion towithin a range of about one fourth of the total. To accomplish thebest results, I prefer to limit the' capacity of the lines of communication so that not more than about 2% of the distillate to be treatd may collect in the lines ofy communication and so that it. may be introduced `into the heating apparatus before mixing with successive distillates from the still.' In this manner, the hydrocarbons within the cracking chamber may be of very limited boiling range.

I may pass the vapors from thepreliminary still through a cooler so as to liquefy them prior to introduction into the cracking-y apparatus and in operating in this manner it is advantageous in liquefying them to cool while the following distillateis collected in another chamber which in Iturn is transferred to the heating apparatus. I may provide a pair or a series of such collecting chambers. In any case, the capacity of such intermediary chambers should be limited to that required to approximately limit the boiling range of the distillate collected to les than that of about one Vfourth of the total distillate to be treated or less than about 100 F. y This latter mode of operation may be effected with or without a ump; the4 fractions may be transferred to t e heating apparatus by a ump, by gas pressure .or in anyr other Well- `nown way.,

As further illustrating this invention, IV may disti'l a keroseneoil with an initial .boil-l ing point of about 350 F. and a final boiling point of about 600A F. collecting four fractions, the first 25% ofthe oil distilling particular temperature and pressure appro priate to each fraction, I obtain a ,much 1n-;

creased yield of gasolineand a gasoline of improved quality. j

Referring again to the drawings, I may supply' crudeI oil or residues or distillates from crude oil, which may or may lnot conf.` tain. gasoline, to the still 10 through connec tion 17. If the material contains gasoline I preferl to .openvalve .32 and first-distilly ofi' the straight run gasoline collecting -it in the receiver 26. After removal of the gasoline, I may continue the distillation, opening valve 43 and passing the vaporsy through cooler 41, collect-ing the liquefied fractions in containers 35 and 36. These containers-preferably are of small capacity, whereby` to automatically limit the boiling range of any liu single fraction collected therein. I may col= lect alternate fractions in one of these 'receivers and then the other, alternately passing the previously collected fraction to the cracking apparatus. Or I may liquefy the vapors as they come from the still and continuously pass the liquefied vapors to the cracking apparatus, maintaining the rate of flow and the capacity of the connections between the still and the converting apparatus such that the distillates submitted to conversion at any one time have but a narrow range of boiling points. Or I may take the vapors directly from the still through valve and conduit 444 to the cracking apparatus. Where the vapors, either condensed or uncondensed, are continuously conducted to the conversion retort from the still, the capacity of the connections between the still and the retort are advantage# ously limited to less than 10%, vor better,- less than 2% of the amount of distillates to be derived from the still charge. Likewise, hot liquid oil from the still or heater 10 may be conducted directly to the retort through connection 21. I find this latter method of operation advantageous for treatment of the final fraction of the original hydrocarbon material to be cracked or decomposed.

The fractions of narrow boiling range in either the vapor or liquid form may be fed into the cracking tube by means of pump 50. Atmospheric or higher or lower pressures may be used. I prefer to pass the oil in countercurrent with the hot gases about the tube 60 in order to insure uniform and gradual rise of temperature and to avoid overheating, and also to i-ncrease theI fuel efficiency. The temperature and within the converting tube 60 shoul be adjusted in correlation with the characteristics of the particular fraction being treated and in accordance with the product desired. .The temperature can be readily controlled by adjustment of burner 66 and the ressure can be controlled by regulation of t e operation of the pum 50 or by regulation of the withdrawal of liquids and gases from the tower 80.

After passing through the heating or converting apparatus I may direct the oil into a tower 80 either with or without preliminary cooling by cooler 76. If the vapors are cooled sutliciently before entering this tower, the tower acts as a trap for the separation of vapors and liquids, but ifithis cooling is omitted or is of lesser effect, the tower acts as a reflux tower. The cooling maybe carried out to such an extent as to liquefy or condense the oil so that it may be removed from the apparatus as a liquid or the oil may be cooled only to such an extent that the heavy constituents are condensed and the light constituents remain as a vapor. Any heavier material collecting in the lower part of the tower may be drawn oil:` through valve 84 or may be returned to the still 10 for retreatment through line 88. The lighter vapors collecting in the upper part of tower 80 may be conveniently collected by being passed through condenser 96 into receiver 90, from which the liquid can be drawn off at valve 91 and the permanent gas removed through connection 94.

The operation of the apparatus illustrated in Fig. 2 is as follows. The vapors from the still are cooled and condensed in condenser 101 and are then collected in small fractions in chamber 104 and 105. A ypair of these chambers may be operated alternately or a series of these chambers may be provided. The distillates collecting in each of these chambers should be of narrow boiling range and I find it convenient for accomplishing this result to limit each chamber to a ca- SJ pacity of less than about one fourth of the total distillate to be treated or preferably less than one tenth of that amount. The boiling range of the distillate collected in any one receiver should not exceed 100 F. The valves controlling the collection of the vdistillate in the various chambers may be controlled by thermostatic or hydrometric action, or they may be manually controlled.

The fraction in each of these receivers may then be directly subjected to a cracking temperature by a suitable heating means such as burners 108 and 109, or they may be converted in other apparatus. I have illustrated the fractions as cracked directly in the receivers 104 and 105 and in this case condensers 112`and 113 and receivers 114 and 115 should be provided to condense and collect the cracked fractions.

It will thus be seen that this invention ro- IUT vides a process for the conversion of hy rocarbon liquids, in which the oil subjected to any given conversion conditions has a relatively narrow range of boiling points, whereby the yield of the desired product is increased, due to the fact that the oil is subjected to optimum conversion conditions, and a product of improved qualities obtained because overheating of any part of the fraction treated is avoided.

It will also be seen that this invention provides'improved apparatus for effecting the conversion of hydrocarbon liquids of hi h boiling point into hydrocarbons of low bolling points in accordance with the invention.

lVhile I have described my invention in detail, it will be understood that many variations will appear to one skilled in the art within the scope of my invention and within the scope of the subjoined claims.

I claim:

1. A process of treating liquid petroleum hydrocarbons for the 'production of lower boiling liquid hydrocarbons which comprises preliminarily distilling the petroleum hydro- 130 raie-,eso

carbons and subjecting the distillate to temperature and pressure appropriate to convert it into lower boiling hydrocarbons while limiting the boiling range of the fraction subjected to conversion at any given instant to less than about 100 F.

2. A process of treating liquid petroleum hydrocarbons for the production of lower boiling liquid hydrocarbons which comprises preliminarily distilling the petroleum hydrocarbons and subjecting the distillate to temperature and pressure appropriate to .convert 1t into lower boiling hydrocarbons while limiting the boiling range of the fraction subjected to conversion at any given instant to less than about 25O F. v

3. A process of treating liquid petroleum hydrocarbons for the production of lower boiling liquid hydrocarbons which comprises preliminarily distilling the petroleum hydrocarbons, continuously passing the distillate through a converting zonewhile limiting the boiling range of the fraction subjected to conversion at any given instant to less than about 100 F., and regulating i the temperature and pressure in the converting zone to correspond to the character of the distillate as the preliminary distillation proceeds.

4 4. A process of treating liquid petroleum hydrocarbons for the production of lower boiling liquid h drocarbons which comprises preliminari y distilling the petroleum hydrocarbons, liqueying the distillate continuously, continuously passing the liquefied distillate through a converting zone while limiting the boiling range of' the fraction subjected to conversion at any given instant to lessthan about 100 F., and regulating the temperature and pressure in the converting zone to correspond to the character of the distillate as the preliminary distillation proceeds.

5. A process of treating liquid petroleum hydrocarbonsfor the production of lower boiling liquid hydrocarbons which comprises preliminarily distilling the petroleum hydrocarbons, compressing and liquefying the distillate continuously, continuously passing the liquefied distillate through a converting zone while 'limiting the boiling range of the fraction subjected to'conversion at any given instant to less than about 100 F., and regulating the temperature andpressure in the converting zone to correspond to the character of the distillate as the preliminary distillation proceeds.

A process of treating liquid petroleum hydrocarbons for the production of lower boiling liquid hydrocarbons which com- Erises preliminar-ily ldistilling the petroleum ydroearbons andr subjecting the distillate to a cracking. temperature and superatmospheric pressure' while limiting the boiling range of the fractionsubjected tothe cracking temperature at any given instant to less than about 100 F.

7. A process'of treating liquid petroleum hydrocarbons for'the production of lower boiling liquid hydrocarbons `which comprises prehminarily distilling the petroleum hydrocarbons, subjecting the distillate `to temperature and pressure appropriate to convert it into lower boiling hydrocarbons while limiting the boiling range of the fraction subjected to conversion at any given instant to less than about 100 F., and separating and returning to the preliminary distillation the higher boiling portion.

8. An apparatus for treating liquid hydrocarbons yfor the production of lower boiling liquid hydrocarbons which comprises a preliminary still,a cracking retort, means for regulating the temperature on the retort independently of the still and means therebetween to conduct the distillate from the preliminary still to the cracking retort, the conducting means being limited in contained` volume to less than 25% of that y'volume necessary to hold the normal charge of the preliminary still.

9. A hydrocarbons for`the production of lower boiling liquid hydrocarbons which comprises a preliminary still, a cracking retort, means forl regulating the temperature on the retort independently of the still and means therebetween to conduct the distillate from thepreliminary still to the cracking retort, the conductingl means being limited in contained volume to less than 10% of that volume necessary to Vhold the normal charge of the preliminary still.

10. An apparatus for treating liquid hydrocarbons for the production of lower boiling liquid hydrocarbons which comprises a preliminary still, a cracking retort, means for regulating the temperatureon the retort independently of the still and means therebetween to conduct the distillate from the preliminary still to the cracking retort, the conducting means being limited in contained volume to less than 2% of that volume necessary to hold the normal charge of the preliminary still. f

11. An apparatus for treating liquid hydrocarbons for the production of lower boiling liquid hydrocarbons which comprises a preliminary still, a cracking retort, and a series ot' conducting means between the preliminary still andthe retort, the contained volume of each of said conducting means being limitedv to less than 25% of that volume necessary to hold the normal charge of the preliminary still, and means to close each oi the conducting means at two points, one adjacent the preliminary still and one adjacent the retort.

12. An apparatus for treating liquid hydrocarbons for the production oflower n apparatus 'for treating liquidv llll boiling liquid hydrocarbons which com-l prises a preliminary still, acrackin retort, and a series of conducting means tween the preliminary still and the retort, the 5 contained volume of each of said conducting means being limited to -less than 10% of that volume necessary to hold the normal Lei-1,930

charge of the preliminary \s'ti1l,' 'and -means to close each of the conducting meansrzat two points, one adjacent thepreliminary 1U still and one adjacent the retort. A Inn testimony whereof I aix my s`gna.

ture .i

AUGUSTE J EAN PARIS, JR. 

